SocialLinkPreviewFetchedNotification

Published when the composer’s link card was read from the page the link points to, before it is returned (and remembered for an hour). A handler can change the title, description or image, for example to add your site’s name or use a different image.

The following properties are available within the notification

Property Name	Type	Settable	Use
Url	string	No	The link the card was asked for.
Title	string?	Yes	The page’s title.
Description	string?	Yes	The page’s description.
ImageUrl	string?	Yes	The page’s image.

Rules

• ImageUrl must be an absolute https URL. Anything else is dropped.
• It isn’t published when the card couldn’t be read (link.not_allowed, link.unreachable), or when a site replaces ILinkPreviewService.
• The person can still change the card in the composer, and everything is checked again when the post is saved.